Electrical storage of information on gas-filled tubes



May 12, 1953 F. H. BRAY ETAL ELECTRICAL STORAGE OF INFORMATION ON GAS-FILLED TUBES Filed Oct. 29, 1947 SENDER. KEY

DICI KEYS FIG IA.

5 Sheds-Sheet l SMPT SEND K2 88/612222? I ga6 ckl'lfl g6 CANCEL KEY SENDEP BUSY LAMP 5.54..

M y 1953 F. H. BRAY ETAL 2,638,506

ELECTRICAL STORAGE OF INFORMATION ON GAS-FILLED TUBES Filed 001;. 29, 194'? 5 Sheets-Sheet 2 May 12, 1953 F. H. BRAY ETAL 2,638,506

ELECTRICAL STORAGE OF INFORMATION ON GAS-FILLED TUBES Filed Oct. 29, 1947 5 Sheets-Sheet 4 CONTROL CATHODE POTENTML I CAP POfENTML May 12, 1953 F. H. BRAY ETAL ELECTRICAL STORAGE OF mommxon 0N GAS-FILL'ED TUBES Filed Oct. 29, 1947 5 Sheets-Sheet s Patented May 12, 1953 ELECTRICAL STORAGE OF INFORMATION ON GAS-FILLED TUBES Frederick Harry Bray, George Clifford Hartley, and Desmond Sydney Ridler, London, England, assignors' to International Standard Electric Corporation, New York, N. Y.

Application October 29, 1947, Serial No. 782,733 In Great Britain October 30, 1946 8 Claims.

This invention relates to registering and controlling means and has for its object further improvements in the application of discharge tubes for such purposes.

The main feature of the invention comprises registering and controlling means comprising discharge tubes both for registering numbers and for counting stored numbers.

To make the invention clearly understood, reference will nOw be made to certain embodiments shown in the accompanying drawings, in which:

Figs. 1A and 1B illustrate an electric counter combined with an electric storage device for use for instance in an automatic telephone system;

Fig. 2 illustrates a code for storing numbers 1 15 on a set of four storage devices, such as neon tubes; I I

Fig. 3 illustrates the method of counting out the record on the counter; I

Fig. 4 illustrates another embodiment of an electric counter; while Fig. 5 illustrates another alternative means for triggering one pair of tubes from another.

These figures are also used to illustrate the invention of our copending application, Serial Nop 782,734, filed October 29, 1947, now Patent No.

The arrangement illustrated in Fig. 1 may be 'used in an automatic telephone system where it is required to select a number by successively operating digit keys, each key corresponding to a digit of the number, to store the number in an electric storing device, and subsequently to send .impulses into a line, which correspond to the number selected, or to respond to revertive impulsing from a distant point.

The circuit arrangement of Fig. 1 illustrates a key-sending position at its left hand side, a storage circuit at the lower part of its right hand side,

and an electric counter at the upper part of its right hand side.

The key-sending position comprises a sender key SK, ten digit keys corresponding to the'numerals 1, 2, 9, 0, a start-send key SSK, a cancel key GK, and a sender busy lamp SBL;

'j The storage circuit comprises eight sets I, v 2, I, 8, each of four circuits a, b, c, d, of neon or the like gas discharge tubes Ta, Tb, Tc, Td, each connected in series with a high ohmic resistor Ra, Rb, Rc, Dd respectively. A neon or the i like tube needs a potential for striking the tube which is considerably higher than the lowest potential necessary for sustaining the discharge through the tube after the tube has been ignited (hereinafter and in the claims shortly called sus- 'taining potential). An operating potential between the striking and sustaining potentials will maintain the tube in either of two different stable conditions. If the potential across the tube has been momentarily raised above the striking potential, the tube will ignite and the discharge through the tube will be maintained and the tube be conducting when the potential has returned to the normal operating potential. If the potential is now momentarily lowered below the sustaining potential, the discharge through the tube will be quenched, and the tube will become nonconducting and remain non-conducting when the potential has again returned to the normal operating potential. Thus, each tube may be in one of two dilferent conditions which may be ascertained by sensing the potential across the respective series resistor. As indicated in Fig. 2, a set of four tubes may assume sixteen different patterns depending on which of the four tubes are conducting, and which are non-conducting. By

selecting ten difierent patterns out of the possible sixteen patterns, each digit may be stored and represented on a binary basis on such a set of fourtubes. In Fig. 2, each row contains four circles corresponding to the circuits (1, b, c, d of a set of four neon tubes each in series with a resistor, the black circles indicating a circuit compnsing a conducting tube and the white circles indicating a circuit comprising a nonconducting tube. Fig.

' 2 illustrates the 16 possible patterns of which ten correspond to the digits 1, 2, 9, 0, these being 7 the only ones used in the example given. Tubes a, b,'c-, d represent ascending orders of numbers scale; 1, 2, 4, 8, and record digits in are provided, which are normally charged from a supply source through the resistors RI R2, R3,

' R4, to the positive operating potential of the gas discharge tubes. The resistors RI, R2, R3, R4 are shunted respectively by additional capacitors Cl, C2, C3, C4. The triggering capacitors are connected in series with resistors R5, R6, R1, R8 for limiting surge currents. In the position illustrated in Fig. l, the triggering capacitors C5, C6, Cl, C8 in series with the respective series resistors R5, R6, R7, R8, are connected across various contacts, which will be described further below, to the anodes of the gas discharge tubes Ta, Tb, Tc, Td, of the first set of tubes of the storage circuit.

The electric counter comprises eight cold cathode discharge tubes CTl, GT2, CTT, CT8. Each of these tubes comprises a cold cathode, an anode, and two auxiliary electrodes for striking the tube. The tubes are arranged to form two sets of four tubes, the first set comprising the tubes CTI, GT3, GT5, CT! and the other set the tubes GT2, CT i, GT6, GT8. The tubes also form four pairs of tubes, the first pair comprising the tubes CH and GT2, the second pair the tubes CT3 and GT4, the third the tubes C'It and GT5, and the fourth the tubes CT! and GT8.

Before a number is selected, the sender key is closed whereby the relay GA is energised. The

contact ga9 of the relay GA is closed for a purpose which will be described further below. The contact ga8 of the relay GA is closed and applies the positive operating potential derived from the supply source to all the anodes of the gas discharge tubes of the storage circuit, the cathodes of the tubes being connected to the respective series resistors, the free terminals of which are connected to the earthed negative operating potential of the supply source. also applies the positive operating potential to the main anodes of all the cold cathode tubes of the electric counter, thecathodes of the tubes of the first set being connected across the primary windings of cathode transformers Tl, T2, T3, T4, and the cathodes of the tubes of the second set being directly connected to the negative terminal of an additional supply source. The contact pct-8 is closed and connects a relay CA to the cancel key CK. The contact gafi connects a relay H to the start send key SSK. The contacts ga5-ga2 connect respectively the triggering capacitors (18,0 3, C6, C5 to the digit keys. The contact gal connects a relay S to the digit keys.

When now a digit key is operated, a certain combination of gas discharge tubes of the first-set of tubes of the storage circuit is ignited in the toll'owing manner: Assume the first digit key to .beroperated is key 5 corresponding to the numeral 5.. In this case, as will be seen from Fig. 2., the

gas discharge tubes In and Th of the first set should .be ignited, while the tubes To and Ta should not be ignited. By operating the digit key 5, the negative terminal of the additional supply source, whose :positive terminal is earthed, is

connected to the capacitors C8 and @CG. Thereby the charges of these capacitors are reversed. The charging currents flow through the resistors Ra and R0 of the first set of tubes of the storage circuit. Thereby, the potentials across the corresponding tubes Tb and I'd are momentarily raised'abov-e the striking potential of the tubes Tb and Tel which are ignited and remain ignited after the digit key '5 has been released. The capacitors Cl, C2, C3, C4 ensure that the ignited tubes are not quenched while the triggering capacitors C6, C8 are recharged on release of the digit .key. The operation oi a digit :key also 'energises the relay S. Its contact a! (see right hand bottomcorner of Fig. :1) is operated whereby theirelay #A is energised yia back'contacts b l-h-l, sl front, cal, cZ2 back. A relay 8.] is energised over the closed contact 142 and is looked over its contact sy'Z to 0Z3 :back. Contact 3413 closes the circuit :-for the sender ibusy lamp SBL, which The contact cat all) commences glowing. Contact s7! is closed without effect. When the digit key 5 is released, the relay S is de-energlsed and its contact sl is released. Thereby, the relay A is locked, right hand winding of B, left hand winding .of A, M front, sl, cal, 012 back. Relay B is energised. The contacts 193-496 disconnect the triggering capacitors C5, C5, Cl, CB from the first set of gas discharge tubes of the storage circuit and connect them to its second set or" gas discharge tubes.

The next operation of a digit key triggers a pattern which represents the numeral corresponding to the respective key on to the second set of gas discharge tubes of the storage circuit in an analogous manner to that just described with reference to the first set of tubes. The relay S is again energised and operation of its contact s! causes the locked relay A to be released but relay B holds via bl-hl. The release of the digit key causesthe relay S to de-energise whereupon the relay C is energised over contacts .122 front, a1, 5! back in series with the locking .the relays B to H, energised on release of the eighth digit key operated and is looked over its contact dsl, While the relay H is released by short-circuit of its left hand winding. If, however, the number to be stored comprises less than eight digits, the start send. key SSK has to be operated after the last digit key has been released. Operation of the start send key energises the relay H over the contacts gas and ds3, whereby the relay DS is, again, energised and, as before, .closes a circuit via a winding of :DS, left hand winding of H, contacts h2--sl, cal .012. The main winding of relay H is de-energised by the operation of the contact ds3, while its locking winding is short circuited by contact dsl which is closed so that relay I-I releases its contacts. In both .cases, the contacts ds4dsl .disconnect thewstorage circuit from the triggering capacitors C5, C6, C1, C8. The contact 1138 disconnects the relay S from the digit keys.

Operation of US also closes con-tact (1S9 associated with two additional cold cathode discharge tubes GT9 and 0TH}, each comprising a cold cathode, a main anode, and an auxiliary anode.

The contact 4152 is closed whereby the relay TB is energised via 153 back, as: front, h2 sl back,

cal, 022 back and looks over trii, 3152, 012.

The contacts :tri4 are closed and-connect the storage circuit to the electric counter to control the transmission of the stored digits into the line ZI and 12. It will further be appreciated that since the number has been stored in a binary "code on the storage circuit, it :has to be transpf theiceld icathode tubes C'Il, GT5, GT3, .CTI

causes such tube to strike.

forming the first set of cold cathode tubes of the electric counter. The tubes are of the type provided with two auxiliary electrodes either of which may b used for triggering the tube. As explained hereinbefore, the relay GA was energised and its contact 9119 closed when the sender key the closed contact 9118, contact ca3 back and anode resistors RI5, RIB, RH, Rl8 respectively.

'The commencement of the discharge currents across the main discharge spaces of the tubes =GTI, GT3, and GT5, which flow through the pri- I mary windings of the cathode transformers Tl,

T2, T3, causes an electromotive force to be momentarily induced in the secondary transformer windings of sufficient amplitude to trigger the cold cathode tubes GT4, GT6, and GT8. These tubes, however, do not sustain since their main anode potential is, at the same time, reduced'by currents charging anode capacitors CH, CH, Gl3. The conditions of. the eight tubes of the electric'counter is indicated in the rows 1, 2 of Fig. 3, row 2 indicating that the cold cathode tubes CTI,.GT3, GT5, GT1 of the first set of tubes are conducting and row I indicating that the tubes GT2, GT4, GT6, GT8 are non-conducting.

Fig. 3 also indicates that the cold cathode tube GTIO is non-conducting.

The anode capacitors Gll, G12, G13 and Gill, which is also charged, are connected between the anodes of the four pairs of tubes, one capacitor for each pair. When any of the cold cathode tubes GT2, GT4, GT6, GT8 of the second set "of tubes of the electric counter is triggered inla manner to be explained hereafter, the charging current flowing through the respective anode capacitor causes the potential on the anode of the corresponding tube of the first set to be sufficiently lowered, so that such corresponding tube is quenched.

In other words, the provision of the anode capacitors ensures that on triggering and striking of one tube (no matter whether it belongs to the first or second set of four tubes) of the electric counter, the other tube belonging to the same pair of tubes is automatically quenched.

Closing of the .contacts trltr4 connectsthe cathodes of the neon or the like discharge tubes Ta, Tb, Tc, T11 of the first set of tubes of-the storage circuit respectively to limiting resistors R22, R23, R24, R25 connected to the lower auxiliary electrodes of the cold cathode tubes GT8, GT6, GT4, GT2 of the electric counter. Any ionised storage tube causes a potential drop across its series resistor which is applied to the said auxiliary electrode of the corresponding cold cathode tube of the second set of the electric counterv and Thereby the other tube of the same pair of tubes is quenched.

In the example discussed hereinbefore in which the first digit key operated was th digit key 5,

' the binary code corresponding to the numeral 5 was impressed on the first set of gas discharge tubes of the storage circuit. Consequently the tubes Tb and Td of the first set of tubes of the storage circuit are ignited and the tubes Taand- Tc are not ignited. This causes a voltage drop across the resistors Rb and Rd of the first set which, in turn, causes the cold cathode tubes GT8 and GT4 of the second set of tubes of the electric counter to strike when the contacts trI-Tr4 are closed. The tubes GT8 and GT4 belong to the fourth and second pairs of tubes of the electric counter. These tubes remain ionised and striking of these tubes causes the other tubes of the fourth and second pairs, namely tubes GT! and GT3, to be quenched as described above. The condition of the eight tubes of the electric counter after the operation of the relay TR is represented in the third and fourth rows of Fig. 3. The pattern corresponding to the digit 5, which is repeated in the last row of Fig. 2 is thus transferred to the second set of tubes of the electric counter (as shown in the third row from the bottomof Fig. 3) th first set of tubes of the electric counter represents a pattern (see fourth row of Fig. 3) that is complementary to that impressed on the said second set of tubes, the tube GTHl being still non-conducting. The cold, cathode tubes contrary to the arrangement of the neons work on the basis that an operated tube represents a binary digit while an unoperated tube represents a zero. The tubes CTI-1 therefore record the number stored while the tubes GT2B record the complement to fifteen.

From an inspection of Fig. 2 it will be seen that the digit code has been chosen in such a manner that any digit requires either tube T0 or tube Td or both these tubes of a set of the storage circuit to be ignited. Consequently, when the pattern has been transferred. to the electric counter either tube GT8 or tube GT6 or both these tubes of the second set of tubes will be ionised. Ionisation of either or both these tubes causes a negative pulse, owing to the sudden change of potential, on the corresponding anode or anodes of the tube or tubes GT8 and/or GT6 which triggers across the capacitor GIS and resistor R3! and/or capacitor GM and resistor R36, th cold cathode tube GT9 which becomes ionised across the discharge space between its cold cathode and anode. Thereby the relay ST is energised. Its contact stl is opened; contact 5132 is opened and de-energises relay TR whereby the cold cathode tubes of the second set of the electric counter are disconnected from the gas discharge tubes of the first set of the storage circuit; contact st3 is closed and prepares the anode-circuit of a cold cathode tube GT! 1; contact 8t4 energises the relay S; contact is closed and connects the auxiliary electrode of the ingof the cathode transformer T4 of the tube GT1; contact stB is closed.

cold cathode tube GTIEI to the secondary wind- An impulse sender Z is connected to the line Z5, Z2, and comprises contact springs ZZ connected across the line Zl, Z2, which are periodically opened and closed so that impulses may be sent into the line ll, Z2 while the contact springs Zl are open. Additional contact springs Zs are provided which operate in synchronism with the springs ZZ. While the springs Zs are closed a relay IG is short-circuited. Now, owing to the contacts W5 and stB being closed the relay IG is energised on the next opening of the contact springs Zs. Its contact igl disconnects the springs Zs from the relay IG which, thus, will no longer be short-circuited when the springs Zs close again, and connects the said springs to the relay I which will be energised on closing of the springs Zs. Contact ig3 is closed (see right hand endof counter) and. discharges a triggering capacitor 09 across a resistor 3.3%, the capacitor EGTl-GTZ which form the first pair of tubes of the electric counter. By the discharge of the capacitor G9 on closing of the contact igfi the nonignited tube of the first pair is ignited. This in turn causes the previously ignited tube to :be

quenched .as hereinbefore described. In the example referred to above, the tube GT2 was not ignited and the tube .G'Il ignited. After operation of the relay IG and closing of the contact .igil :the tube GT2 is ignited and the tube CT! is not ignited. The condition of the eight tubes .of the electric counter after the operation of the :relay IG is represented in the 5th and 6th rows of Fig.

3, the tube G'Tiil being still non-conducting. The condition of the upper set of tubes now corresponds to digit 4, Fig. 2. It will be seen that an impulse has been interpolated prior to synchronous impulsing both to line 1112 and to the counting tubes. This is because it is desired not only to count out the digit to the condition shown in rows 13, M, Fig. '3, but to return these tubes to the original condition shown both in rows 1,2 and rows l5, 56, Fig. 3.

When the springs Zs close again, the relay I is energised and causes the contact i l to open.

Thereby, the triggering capacitor C9 is recharged.

Contacts igz remove the short-circuit from springs 21 but not in time for an impulse to be :3

sent to line during the opening of springs Zs, '21 which causes operation of IG. When the springs .25 open again, the springs .21 alsoopen allowing the impulse sender to send a-first impulse into the line li, l2, which is no longer short-circuited by the contact 15 2. On opening of the springs ;Zs, the relay I is de-energised, whereby the contact ii is closedagain and the capacitor C9 discharged, the contact 1'93 being closed. The release of the relay I thus causes, in the example assumed, the

through the secondary winding of its cathode transformer T2 which is connected across resistors R23 and R32 to the auxiliary electrodes .of the "third pair of tubes GT5 and GT6. Thereby, in the example assumed, the tube GT5 of the first set is quenched and the tube GT5 ignited. Since the ignited tube GT6 of the third pair is not :as-

sociated-with a cathode transformer, the tubes of a the fourth pair are not triggered, the condition 'of the counter being indicated by the 7th and 8th rows from the bottom of Fig. 3, the tube It being still not ignited. This further impulse to the counter has altered the setting of the second [set of tubes from digit 4 to digit 3. When the springs 21s close again .the relay I is energised, contact ii is opened, the triggering capacitor C9 ,is charged, and on opening of the springs Zs'the relay I is released for the second time. A second impulse is sent into the line ll, Z2 owing to the simultaneous opening of the springs Zl. Again,

the cap C9 is dischar e whereby the tube via the charging circuit of CH GT2 :of the second set is ignited and the tube "of the first set is quenched. Since the ignited tube belongs to the second .set no further tube is afiected, the -.condition of the electric counter being now represented by the 19th and 10th rows of .3, corresponding to digit '2. The springs Z2 and Zs continue to operate in the manner described, whereby the relay I continues to be alternately energised and .de-energised. On each release of the relay I an impulse is sent into the line Z1, Z2 and the first group of cold cathode tubes of the electric counter "is triggered whereby the pattern on the electric counter is changed in the -manner just described, the pattern after the third release of the relay I being shown in the lit-h and 12th rows .ofiFig. 3, that after the fourth release in the 13th and 14th rows and that after the fifth release in the 15th .and 16th rows of Fig. 3. It will be seen that after the fifth release all the cold cathode tubes of the first set are ignited and those of the second set quenched. Tube .GTlO is also ignited as will be described below. The digit code shown :in Fig. .2 has been :so chosen that if any numeral, say for example numeral 5 or 8, has been stored, the condition of the tubes of the electric counter indicated in rows I5, n6, Fig. 3, will be reached after a corresponding number in the .example 5 or 8, of releases of the relay I, and after .a .correspond-ing'number of impulses, one oneachrelease of this relay, has been sent into the linelljl2. Furthermore, it will be recognised that whichever of the patterns of Fig. 2 is impressed on the record set of cold cathode tubes from the storage circuit, GT7 will be quenched either immediately if the pattern is that of digit 1-? or after one or more pulses to the counting set, and is only reignited when the condition shown in the top row of Fig. .3 has been reached.

Jae-igniting of thetube GT7 causes an impulse to be sent through the secondary winding of the cathode transformer T8, whereby the cold cathode tube aCTI'D is ignited, the contact sit being closed. Thereby the relay T is energised. Its contact tl quenches the tube GT9 and completes theanode circuit for tube GTE I; contact t2 short- .circuits the line 1!, l2, and prevents further impulses from reaching the line; contact it changes over; contact t l disconnects the relays I and IG from battery. Quenching of the tube GT9 causes 50 relay S is de-energised whereby the contact cl the "relay "ST to be ole-energised. Thereby, the

returns to normal. When 51 operates S, the

' change-over of contacts s operated relay A as pre viously described. Release of s new energises B in series with A and connects second set of storage tubes to contacts trl-1l so that when eventually relay TR is re-energised, this second set of tubes will be connected to the electric counter. Contact ti also causes a capacitor "(M8 to be charged through a resistor R49 via 51%, i1, (189, R26, positive battery, the time needed for charging the capacitor .CIJB providing a time interval between successive groups of impulses sent into the line and corresponding successive digits. When the capacitor G18 has been charged, the

cold cathode tube GTII ignites and discharges Relay ID is energised. Contact id! is closed and causes the capacitor CIB to discharge; contact icZZ switches over, whereby the cold cathode tube CTN) is quenched and a positive potential applied to the main anode of the cold cathode tube GT9. Gontact ids is closed and energises the relay TRyia $662, .012 back. Thereby the contacts trl-A are closed and the electric counter is connected to the second set of tubes of the storage circuit and is ready to receive, therefrom, the pattern previously impressed the second digit of the stored number. counter, again, operates as before.

'If eight digits have been stored the relay H, after the eighth digit has been counted and transmitted into-the line, causes a clear down relay CL to be energised over the contacts t3, 1252, hi! to b2, al, si, cal, Z2. Contact cll locks the relay CL across contact sil which is closed, relay SJ having been operated on the first operating of relay A andhavingremained locked thereafter via s72, (:13 to light the sender busy lamp SBL. Contacts 022 and 0Z3 are opened and release all the relays. The release of the relay SJ opens contact sa'i whereby the clear down relay CL itself is released, while contact s53 opens and extinguishes the sender busy lamp. 1 v

If less than eight digits have been stored, the arrangement clears down when no code is transferred from a set of tubes of the storage circuit The to the electric counter, since if no code is present neither of the cold cathode tubes 0T8 and GT6 will be ignited. Therefore, the cold cathode tube CTS is' not triggered andrelay ST is not ener ised. The clear down relay CL, which is slow to operate, will now be energised across contacts 371, trl, which are both closed, and contact sit! back. 0D- eration of the relay CL clears down the arrangement in the manner just described."

' If an incorrect digit has been keyed, the cancel key CK may be operated to restore the storage circuit to its initial condition. On operation of the cancel key relay CA is energised. Contact ca3 is opened, whereby the potential across all the neon or the like tubes of the storage circuit is lowered below the sustaining potential and all the tubes which may be ignited are quenched. Contact cal is opened and de-energises any of the relays A H which may be energised. When the cancel key has been released, the relay CA is de-energised' and the circuit is in its initial condition ready for operation.

Itwill be realised it would be possible to replace the combination of set of storage 'neons and the common counting tube assembly by a series of counting tube assemblies each directly marked from the keys or by other marking means.

Modifications of the arrangement illustrated in Fig. 1 are possible. For example, in the electric counter the cathode transformers Tl, T2, T3, T4 may be replaced by capacitors combined with a rectifier, for example, a dry rectifier, or by neon tubes on the lines described later.

' A circuit diagram of such a modified'electric counter is shown in'Fig. 4, which will'now be described. The arrangement of Fig. 4 comprises eight cold cathode tubes CTOi, CT03, CT05, CTO'I forming the first set of tubes, and CTO2, CT04, (BT05, CTO8 forming the second set of tubes. Each tube has a cold cathode connected across a resistor R0 R03, R05, R01; R02, R0 4,

R06, R08 respectively to the negative potential of the additional supply source. the positive terminal of which is ,earthed. The anode of each tube has, in operation, applied to 'itthe positive operating potential derived from the main supply source (not shown) whose negative terminal is earthed. Each tube has two auxiliary electrodes,

for triggering the tubes. One auxiliary electrode ofieach tube of the second set is connected across aresistor'R036, R035, R034, R033 respectively to terminals TOI, T02, T03, T04 for triggering thereon and corresponding to the release of some of these tubes and thereby impressing a digit code on the tubes of the first set. The other auxiliary electrode of each tube of the second Set is connected across two resistors ROIB, R09; R0l2, ROH; R054, R013; R056, R015, respectively to an auxiliary electrode of the corresponding tube of thehfirst set. The other auxiliary electrode of each-tube of the first set is connected across a resistor R02l, R022, R023, R024, re-. spectively to a triggering capacitor C09 charged from the additional supply source across resistors R025, R025. The cold cathodes of the tubes of each pair are ther triggering capacitor C010 is connected to the resistors R09, ROM, and is charged from the additional supply source across resistors Roll, and R027.

a rectifier MRA, MRB, MRO, 1VRD respectively,

the other terminal of which is respectively connected to an electrode of a capacitor C05, C06,

C01, C08, the other electrode of which is re-' spectively connected to a resistorR0l8, R019, R020, R032, the free ends of which are earthed.

The said other electrode of each of the capacitors 1 C05, C06, C01, is also connected respectively t0' the pair of resistors ROI 1, R012; R,0I3,'R0Hl; ROI5, ROIG, while the said other electrode of capacitor C08 is connected to a terminal T05. The capacitors C05, C06, C01, C08 are connected to the positive terminal of an auxiliary supply source whose negative terminal is earthed,

and are charged respectively over the pairs of resistors R028, R018; R029, RON; R030, R020;

R03l, R032. A start relay STO is connected between the additional supply source and a terminal T06 and an impulse relay IPO is connected between the additional supply source and a terminal'TO'I.

- The operation of the arrangement is as follows: The start relay STO is energised by applying earth potential to its terminal T06. The contactstol is closed and discharges the triggering capacthe current limiting resistors R09, ROIU to the auxiliary anodes of the tubes CTOI, CTO2 of the first pair of tubes. ducting. Tube CTO2 is triggered and ignites.

Owing to the voltage drop across the resistor" R02, the potential of the cold cathode of tube CTO2 rises from its original negative potential to a positive potential," which equals the difference between the positive potential applied to the anode and the drop of potential across the main discharge gap. This rise in potential discharges the cathode coupling capacitor'COl, which causes the cathode potential of the tube CTOI to increase positively and to reduce the potential across the main discharge gap of the tube CTOI which is therefore de-ionised and. ceases to conduct. Thus, tube CTOI is now quenched'and tube CTOZ'ignited. More generally, whenever a tube ignites the other, previously ignited,"tube of thesan le group'is quenched owing to the now of connected together across capaci tors 00!, C02, C03, C04 respectively. A fur- The cold cathode of eachtube of the second set is connected to one terminal of Tube CTOI is already con-' a discharge current from the respective cap qitQr C01, C02, cos, 004.. Quenching of the tube CTOl and igniting of the tube CTOZ which be,- longs. to the second set does not affect the. tu s CTQ3 and CTO4 of the next succeeding group since the cathode potential of the tube CTQZ- does not rise above the positive bias potential applied, to. the biassingresistor R028. and the rectifier MRA presents a high resistance to the flow of current in the direction from the resistor 3.028, to. the cathode, of tube CTOZ. When the. r lay IPO, is. de-energised', its. contact ipol is released andv the triggering capacitor COIU. i charged again.

The. secondp rat on of theim u se relay BQ,. again, closes the contact z'pol, whereby the. triggering capacitor C010. is, again, dischar ed. Thereby, the tube CTQI. or the firstgroup is ncw ignited and the tube CTOZ of the. first; g'rQup quenched; in a manner analogousto. that. just; (les scribed- However, when a tube such as. tube. GTQI, of the first set: of tubes ig itesatrig er impulse. is transmitted to the next; succeeding, group, so. as to ignite: that tube which waspreiziouslynot ignited. and to quench the other tube. If the tube nowig-nited belongs to. the first. set. a triggering impulse is-, again, transmitted. to the. follow r up, and. so on. This eiiectwiii now be explained With reference to. the first. group of tubes. tube. of the. first. set. and belonging, to. anyv other group ignites. Whentube C'I'Ol ignites, the dis.- charge current. from the capacitor C0! momentarily raises the potential on the cathodeof the tube GFIOZ sufiiciently to quench. the tube CTOZ; The. cathode potential of: the tube C1702; 1 5.1110: mentarily higher than the positive biassing volt: age. across. the resistor R028. Therefore, a current flows from; the cathode of: the tube CTOZ: across the rectifier MIRA to the resistor R0.2.;8:;and auses. a positive trig erin impulse. to, be transmitted across the capacitor CO5 to. the resistors. RQt r, BQLZJ- This imnulsecauses the tube (3736.4: to. ignite. whereupon. the tube c1103; is-.quenched..

In an. analogous. manner successiveoperaticnsi or: the impulse. re ay. 1280: and; its. contact. i240]; ause he tu.bes=.C.fI0. l: and (11302:: alternatelytobe ignited and; quenched; As explained; above). wheneizer t be of1the-first set i nit s; atrig eb s; mnulseis transmitted: tathe nentsucceedingroup Qfztubes- Qnithesix eenth.oneration-ofi'th irn-p ulserelag IBQ andLits contactipek, tubeC'IiOl is n ed. and: ube CTIQB' is; quenched.=. I niting at the tube: 05501.. which bel nsstc. thenrstseti. causes; ncs t ve. ri e ngmpulse to be sent acr s; theapacitor 69.8.: to. the term-mar. T05.- which. m u e; may be employed: to; oper.ate. an.- i. 'l amc ro i-t not-shown) thereby-to ind ate he counter has; countedsixteen impulses; -W. r a. ly to; rec ye. a fur her setiof sixteens mnu es.

i. the electric. coun er isrequired; to count less; sixte n. impu ses. it. be DU 317: by; i s. messing a. suitable pattern of. positive potentialsv o. erminals 2 1... 110.2,. 03.. 1104;. causingthe. or: .snond ng. tubcsqi hesecond set-.tabetrig-i set nd. o s: e-. Eon examplaif: the. counten su ed i anarraneem nt similar-to that-time. he... er ina sv 13 L. .02.1203; Toll; should. be.- onn c sd. to e s e or side of. the? contacts.- l. 1. r sp ct ely o E la athe Contact TOE-bee; n r nn oted to the l xiliaryanode ofitube 0mm; of Big, 1; triggering connectionsrsimilar to those- Shown. nv ig. 1 being.- provided from: the: tubes A similar efiect. takes; place whenever a ds of Fi l, and. the relays S20. and; IE0 at F st-3r being respectively re laced by the.- relays GAand I of Fig. 1,. Conversely, with obvious; modifications, the electric counter of Fig. 1 maybe used. independently from the remainder of Fig... 1 for counting sixteen impulses, or less impulses if suitably pro-set.

In Fig. 5, which shows the last. two pairs of tubes of a counting set, a small neontube, e. g.

. N3. N4 replaces the rectifier network shown- Fig. 4. This arrangement; has. the advantage of simplicity.butmay not be. so. flexible as the rectifier network. The potential changes. are, the same as; before. The. positive peak potential occurs when GT6 is; de-ionised. is used to. trigger the next pair of tubes. Since th levelof peter!- ti, across. R2 is too high, a, neon N3 is;- arranged in crie such thatv the potential rop across the isch e ap of he ube reduces the. potential: applied to the control electrodes of the next. to; therequired value.

It. will be appreciated that; it, would be possible, to insert. a cross-connection frame betweenthe storage sets-ofv Fig, 1 and the co nting sets: so, that. translated digits. are; sent out.

What is claimed is;

1;. A system tor'the; electricalstorage of: inforation comprisi pl rality of stor ge elements grouped ac r ng. t code: requi m nts. apin;- rality of digit key switching; means. means. renonsive he op tion 0.1? idzkev switch-inst means for selectively electrically connecting; 8;. gnoup of) said storage elementsptqsaids switchin eans, and av plur y of direct-' urrentoperatest tri gerin me ns-,, comm n: to. all; said ro ps ai s e e men s: nd ncluded said. elecri al. nne in m ns. ach. of. s id.s.t.otage.-e1.ee its: ei on ra v yr sponsive. to the. opera ion of. a sep rate one of: said; i ering means; when onnecte to Said rig ering. means but said; o ec n means. said. tri gering;- means'. being. selectivelyoperatively responsive in combinations: o e. Operatio o each digit: key switching means, whereby each digit key switching means:

when operated;selectively'operatesa combination.

charge devices; being capable of'assuming either? by theoperation of one of said key switching CT08; CTOG; ofEig. 3 to tube G'I'S andmontact 75;:

of, said triggering means and thus operates. a predetermined combination. of: the.- connected: group of, said storage elements corresponding: to: the digital; value. of; said digit; key switching? 7 means; on. a. codal; basis;

2; A. registering and" controlling system-romantomatic telephonycomprising a. plurality of elec:-- tron. discharge devices arranged in groups; ac cording tocodal requirements, each: of" said of two conditionswoi-stability,.a plurality-'of'directa current: operated? triggering: means common. to .all said groupsof discharge devices, means fbPSBTBGr tively connecting all' of? said triggering: means;

individuallyto a group ofsaid devices, and digit; key. switchingmeans selectivelyelectrically connected to said triggeringrmeansfor controlling said. connecting. m'eans and for operating predetermined' combinations. of: said triggering means.

. means for normally.- maintaining said discharge:

devices in-one-=conditiorr of- 'sta'bility; eachaof-saidl discharge: devices: being responsive to the opera-- tion of atriggering device connectech to it for shiftingt'ovits other condition ofstability; wheres means will operate 7 a predetermined combinationof' triggering means: which in turn: will shift acorresponding combinationofa group of said dischargedevices from one condition of stability 3, A system for the electrical storage of information comprising a plurality of electron discharge devices arranged in groups according to codal requirements, a plurality of triggering means common to all of said groups comprising a plurality of direct-current operated triggerin elements corresponding to the number of discharge devices in a group, means for electrically connecting said triggering devices to a group of said devices with said triggering elements respectively connected to the devices of said group, a plurality of digit keys connected to said triggering means, each digit key operative to control predetermined combinations of said triggering elements, and stepping means responsive to the sequential operation of said digit keys and included in electrical connection between said triggering means and said discharge devices for controlling said connecting means to connect said triggering means sequentially to said groups of discharge devices.

4. A system for the electrical storage of information comprising a plurality of electron discharge devices grouped according to codal requirements, a plurality of triggering means electrically connected to said discharge devices and comprising a triggering element for each of said discharge devices of a group, said triggering elements being common to all said groups, and a plurality of digit keys connected to said triggering means and operative to control predetermined combinations of said triggering elements, stepping means sequentially responsive to said digit keys included in said electrical connection between said triggering means and said discharge devices for stepping said common triggering means to an untriggered group of said discharge devices, said stepping means comprising a plurality of first electromagnetic relays, one relay corresponding to each group of discharge devices, said relays being serially connected to each other, a source of potential connected to each of said relays, a second electromagnetic relay, circuit means connecting said second relay to said digit keys and said source of potential so that depression of said digit keys is operable to energize said relay and release of said digit keys is operable to ale-energize said relay, signal contact means responsive to said second relay included in the series circuit of said plurality of first relays, plural contacts associated with said plurality of first relays and operable sequentially to step the operation of said relays in response to successive operations of said digit keys, additional contacts controlled by each of said plurality of first relays included in said electrical connections between said common triggering means and said discharge devices whereby successive operation of said digit keys sequentially energizes relays to step the connections of said common triggering means to successive groups of discharge devices.

5. A registering and controlling system for automatic telephony comprising a plurality of gas filled discharge devices grouped according to codal requirements, each of said discharge devices having two electrodes and capable of assuming two conditions of stability depending on the voltage applied across said electrodes, an initiating switch, a first source of potential, an electromagnetic relay serially connected between said initiating switch and said source of potential, 2. first contact responsive to said relay for applying said source of potential to common electrodes of said discharge devices, a plurality of resistors each serially connected to another electrode of said discharge devices and to a common junction, said discharge devices being maintained in one of the conditions of stability by said source of potential, a plurality of digit keys, a second source of potential connected to said digit keys, second contacts responsive to said relay for connecting said digit keys to a first group of said discharge devices, plural triggering means included in said connections between said digit keys and said discharge devices, said triggering means corresponding in number to said discharge devices of a group and being common to all such groups, wherein said triggering means comprises a plurality of capacitors, one corresponding to each discharge device of a group, a plurality of resistors serially connected respectively to said capacitors and said first source of potential for maintaining a charge on said capacitors, said digit keys being operable to connect said second source of potential to predetermined combinations of said capacitors for reversing the charge on said capacitors, whereby said charging currents fiow through said resistor means serially connected to said second electrodes of the discharge devices thereby raising the potential on those discharge devices corresponding to the capacitors of the predetermined selection to change their condition of stability.

6. A registering and controlling system for automatic telephony as claimed in claim 5, wherein each of said plural triggering means is connected in series with an additional resistor for limiting the surge current on charging and discharging said triggering capacitors, and each of said triggering means is connected in parallel with an additional capacitor to prevent said triggered discharge devices of a group from being quenched when said triggering capacitors are recharged on release of said digit keys.

7. A register sender for automatic telephone systems comprising a plurality of discharge devices grouped according to code requirements on a binary basis, said devices being capable of assuming two conditions of stability, a set of keys, means electrically connecting said discharge devices to said keys, means operative upon the actuation of a key of said set to operate predetermined combinations of said discharge devices of a group to register in binary code form a number representative of the digital value of said key, and additional means actuated by said ke'y set upon release of a key for stepping the connections of said last named means to a different group of said discharge devices.

8. A register controller comprising a plurality of electric storage devices, each comprising members adapted to assume one or the other of two conditions of stability for storing each digit of a number in a separate device in a pattern corresponding to a binary code for the digit, means normally maintaining said members in one condition of stability, a plurality of triggering means, each of said members of said storage devices being adapted to shift to its other condition of stability when a triggering means connected to it is operated, a plurality of digit key switches, circuit means electrically connecting each of said digit key switches to a difierent combination of said triggering means, each of said triggering means being adapted to operate When a digit key switch connected to it is operated, stepping means comprising relays actuated by the operation of said digit key switches, contacts operatively associated with each of said relays, electrical con-,

necting means including said contacts for con- 15 16 meeting said triggering means; respectively to the members of successivs of said electric. 'starage.de Refiemnfifis M m the 111% of thlspatent vices. when said relays are successively Qperated, STATES; PATENTS and means. for operating said relays; in. succession s Number Name Date by successive aperatlonof said digit. key SWIGChEb',, a whereby successive operatiian of said. digit; key g'f fi t g" switches operatssselective members of said stmtgf j' a s: f 1943. age devices, sand dfiVlCBS; being sequentially con- 3114 Meaghan l Apr. 27;

nected to said: triggering means: by operation of saidv relays... m,

EREDERIQK BRAY. GEORGE CLIFFORD DESMQND'SYDNEY RIDLEEL. 

